When I'm using one of my clicker knives under my 1 ton arbor press, I'm usually walking it around the knife on 2.4mm veg tan with a 6mm silicone cutting board underneath and it's not easy on some bits to feel when it's gone through and sometimes I'm halfway through the silicone mat. One time I went all the way through. I know the rubber clicker type mats are really expensive but it's something I might have to consider. Doesn't need to be large. Say 6inch square at least and preferably around 10